Snap freezing, or flash freezing, is the process by which samples are lowered to temperatures below -70°C very rapidly using dry ice or liquid nitrogen. Snap freezing achieves the same endpoint as slow rate-controlled freezing, but at approximate rate of -10-1000°C/min, compared to -1°C/min. Snap freezing with a CoolRack® module will provide sample vessel stability, organization and consistent freezing parameters, rapid hands-free sample processing while avoiding lost or contaminated samples. Snap freezing is performed on a pre-cooled CoolRack, which ensures fast heat transfer. This method can provide excellent specimen integrity and a wide array of options for analysis, including extraction of proteins, DNA and RNA for use in research and diagnostics. The following protocol describes a general procedure for cryopreserving bacteria for long-term storage. Verify with your laboratory SOP for specific needs for each strain.